Add QSettings(Scope...) constructor to QSettings

Because of the system specific folder/filenames (organization
name vs domain) it was not possible to explicitly access the
settings with SystemScope without using #ifdef, as it is done
by Qt internally. The new constructor uses the default name
while creating an instance with a scope.

[ChangeLog][QtCore][QSettings] Added QSettings(Scope...)
constructor to avoid using #ifdef in Qt applications.

Change-Id: I81016430a1d18a382bfdd1e1cf32de367f98d7aa
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@qt.io>
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>

1 files changed, 39 insertions, 6 deletions

diff --git a/src/corelib/io/qsettings.cpp b/src/corelib/io/qsettings.cpp
index 8b9f7bc9e5..4a9b2a7261 100644
--- a/src/corelib/io/qsettings.cpp
+++ b/src/corelib/io/qsettings.cpp
@@ -64,8 +64,8 @@
 #include "qrect.h"
 #endif // !QT_NO_GEOM_VARIANT
 
-#ifndef QT_NO_QOBJECT
-#include "qcoreapplication.h"
+#ifndef QT_BUILD_QMAKE
+#  include "qcoreapplication.h"
 #endif
 
 #ifndef QT_BOOTSTRAPPED
@@ -2660,9 +2660,10 @@ QSettings::QSettings(const QString &fileName, Format format, QObject *parent)
     called, the QSettings object will not be able to read or write
     any settings, and status() will return AccessError.
 
-    On \macos and iOS, if both a name and an Internet domain are specified
-    for the organization, the domain is preferred over the name. On
-    other platforms, the name is preferred over the domain.
+    You should supply both the domain (used by default on \macos and iOS) and
+    the name (used by default elsewhere), although the code will cope if you
+    supply only one, which will then be used (on all platforms), at odds with
+    the usual naming of the file on platforms for which it isn't the default.
 
     \sa QCoreApplication::setOrganizationName(),
         QCoreApplication::setOrganizationDomain(),
@@ -2670,7 +2671,20 @@ QSettings::QSettings(const QString &fileName, Format format, QObject *parent)
         setDefaultFormat()
 */
 QSettings::QSettings(QObject *parent)
-    : QObject(*QSettingsPrivate::create(globalDefaultFormat, UserScope,
+    : QSettings(UserScope, parent)
+{
+}
+
+/*!
+    \since 5.13
+
+    Constructs a QSettings object in the same way as
+    QSettings(QObject *parent) but with the given \a scope.
+
+    \sa QSettings(QObject *parent)
+*/
+QSettings::QSettings(Scope scope, QObject *parent)
+    : QObject(*QSettingsPrivate::create(globalDefaultFormat, scope,
 #ifdef Q_OS_MAC
                                         QCoreApplication::organizationDomain().isEmpty()
                                             ? QCoreApplication::organizationName()
@@ -2710,6 +2724,25 @@ QSettings::QSettings(const QString &fileName, Format format)
 {
     d_ptr->q_ptr = this;
 }
+
+# ifndef QT_BUILD_QMAKE
+QSettings::QSettings(Scope scope)
+    : d_ptr(QSettingsPrivate::create(globalDefaultFormat, scope,
+#  ifdef Q_OS_DARWIN
+                                     QCoreApplication::organizationDomain().isEmpty()
+                                         ? QCoreApplication::organizationName()
+                                         : QCoreApplication::organizationDomain()
+#  else
+                                     QCoreApplication::organizationName().isEmpty()
+                                         ? QCoreApplication::organizationDomain()
+                                         : QCoreApplication::organizationName()
+#  endif
+                                     , QCoreApplication::applicationName())
+              )
+{
+    d_ptr->q_ptr = this;
+}
+# endif
 #endif
 
 /*!